This invention relates to a printing office machine including an ink ribbon cartridge which may be readily attached to or removed from a receiving unit mounted on a printing carriage which is movable along a record carrier, such as paper. On the carriage there are arranged a printing head which produces an alphanumeric full-print character on the record carrier with the interposition of the ink ribbon and a drive mechanism for advancing the ink ribbon. The office machine further has a reversible drive motor for the forward and reverse feed of the record carrier.
Since typewriters are being used in ever-increasing frequency as output devices for computers, it is desirable to equip the typewriters with devices that are capable of color reproduction of graphs or graphics. The multicolor plotters of prior art constructions, however, have been very expensive; they have required significant space and therefore are not adapted optimally for use in the home for personal computers.
While line drawing devices (plotters) mounted on typewriters for producing horizontal or vertical lines are well known in many varieties, they are, however, not often encountered in practice. This fact indicates that their usefulness is still in question; one reason therefor may be their drawback that they have been obstructing the normal printing process to an excessive extent.
German Patent No. 891,271 discloses a threaded holding sleeve mounted by a clip to the left or to the right on the plastic line plate next to the character guide head for receiving a threaded ballpoint pen cartridge. Such an arrangement interferes with the normal typing operation particularly in machines in which the printing head is mounted on a carriage which is movable along the record carrier. Also, a replacement of the ballpoint pen cartridges requires particular skill on the part of the machine operator.
Further, German Offenlegungsschrift (application published without examination) 3,315,733 discloses a multicolor plotter which has styli of different color arranged on the periphery of a drum-like holder. The setting of the plotter to the desired color is, however, very complex. In addition, German Offenlegungsschrift 3,619,567 to which corresponds U.S. Pat. No. 4,813,796 describes a shifting element provided with a stylus which, by means of a manually operable device mounted on the shifting element, may be set from an inoperative position to a ready-to-write position. While this plotter permits the drawing of simple lines in a horizontal, vertical or any other direction, the setting of the shifting element must be effected manually. For this reason, the device is not adapted for an automatically operating printer.
German Patent No. 3,140,888 discloses a plotter which has writing elements shiftable in the direction of the record carrier. The writing elements are colored styli and are arranged in a drum-shaped holder. While this multicolor plotter is adapted to produce graphic patterns in color, it is not readily adaptable to a simple typewriter.
It is further noted that no carbon copies can be produced with the above-outlined known drawing devices.